Slit exposure device for a reproduction apparatus

ABSTRACT

An optical scanning and reflecting system is disclosed for use in a document copying apparatus in which photosensitive paper is exposed by the image of an original document. Light from the original document is reflected by three moving mirrors through a fixed lens and is projected through a slit upon photosensitive paper which is moved in coordination with the movement of the three reflecting mirrors. Two mirrors move in a plane parallel to the original document and the third mirror moves perpendicular thereto.

United States Patent Koizumi [4 Mar. 14, 1972 [5 SLIT EXPOSURE DEVICEFOR A References ed REPRODUCTION APPARATUS UNITED STATES PATENTS [72]Invent Japan 3,330,181 7/1967 Jakobson ..355/66 Assignee: KabushikiKaisha Ricoh Tokyo Japan Williamson 3,431,053 3/1969 Wick et a1 ..355/66[22] Filed: Sept. 5, 1968 Prima Ex minerJose h F. P ters Jr. 21 A LN757,537 a P e i I pp 0 A wa YYBEQIKEEWE [30] Foreign ApplicationPriority Data [57] ABSTRACT Sept. 20, 1967 Japan ..42/60357 An opticalscanning and reflecting system is disclosed for use in a documentcopying apparatus in which photosensitive [52] [1.8. CI ..355/65, 355/8,355/84, paper is exposed by the image of an original document. Light355/100 from the original document is reflected by three moving mir-[51] int. Cl .....G03b 27/16, G03b 27/30 rers through a fixed lens andis Projected through a slit p [58] Field of Search ..355/8, 44, 45, 66,77, 81, photosensitive P p which is moved in coordination with themovement of the three reflecting mirrors. Two mirrors move in a planeparallel to the original document and the third mirror movesperpendicular thereto. 1

7 Claims, 3 Drawing Figures Patented March 14, 1972 SLIT EXPOSURE DEVICEFOR A REPRODUCTION APPARATUS The present invention relates to animprovement in a slit exposure device for a reproduction apparatus withan exposure slit.

It is an object of the present invention to provide a compact slitexposure device.

According to the invention, this is achieved by a system of threerelatively movable reflecting mirrors which scan an original andtransmit an image thereof to advancing photosensitive paper.

For a better understanding of the invention, reference is made to thefollowing detailed description of the invention taken in conjunctionwith the accompanying drawings wherein:

FIG. I is a sectional view of the slit exposure device of the invention,which shows the state at the beginning of exposure;

FIG. 2 is a sectional view of said device when it has finished theexposure; and

FIG. 3 is a diagram illustrating the principle of the invariance of theoptical length in the invention.

A glass plate 2 is fixed at an upper hole 17 of the housing 1 of thereproduction apparatus and serves as an original set stand for anoriginal 3. The inside of the housing is divided into five parts, i.e.,an illumination part In, a slit part lb, a roller part 10, an electriccontrol part 1d and a developing part 1e. In the illumination part la,there are a first moving reflection mirror 4, a second moving reflectionmirror 5, a third moving reflection mirror 6 and illumination lightsources 7 and 8 with reflector shades, all of which can move in the partla. The first moving reflection mirror 4 makes an angle of 45 with theoriginal surface 3, the second reflection mirror 5 makes an angle of2230 and the third moving reflection mirror 6 makes an angle of 6730with the surface respectively. The first reflection mirror 4 and theillumination light. sources 7 and 8 can move as a unit in the directionparallel to the original surface as shown by arrow A through a suitablemotor drive mechanism. In accordance with this movement of the firstreflection mirror 4, the second moving reflection mirror 5 can move inthe direction perpendicular to the original surface as shown by arrow Band the third reflection mirror 6 can move in the direction parallel tothe original surface as shown by arrow C. Moreover, at the boundarybetween the illumination part la and the slit part lb, there is provideda hole 18 and a lens 9 is fixed with its optical axis making 90 with theoriginal surface. In the roller part Is, a roller shaft 10 is installedon which a roll of photosensitive paper 11 can be mounted. Thephotosensitive paper 11 can be drawn out by a suitable drive mechanismin unison with the movements of the moving reflection mirrors 4, 5 and 6and the illumination light sources 7 and 8. In the moving path of thephotosensitive paper 11, there are a cutter 12 for cutting thephotosensitive paper 11, a charger 13 for charging the photosensitivepaper 11 through corona discharge, a guide roller 14 and aphotosensitive paper receiver 15. In the electric control part Id, thereare a power transformer, a motor drive mechanism and other electricmeans, and the developing part 1e is filled with developing liquid 16.

The slit exposure device of the invention is composed as describedabove, and when an original is placed face down on the glass plate 2 anda switch in the electric control part 1d is turned on, the illuminationlight sources 7 and 8 are turned on and the s$rface of the original isilluminated. At the same time, the first moving reflection mirror 4 andthe illumination light sources 7 and 8 begin to move as a unit in thedirection indicated by the arrow A from the state shown in FIG. 1, andthe second moving reflection mirror 5 and the third moving reflectionmirror 6 move in the directions of the arrows B and C respectively.Meanwhile, the photosensitive paper 11 moving in synchronism with thosemovements, is charged negatively by the charger l3 and passes the endface of the slit part lb. The light from the original surface isreflected by the reflection mirrors 4, 6 and 5, passes through the lens9 and makes an image on the photosensitive paper II. In this way, theimage is exposed through each slit in sequence and when the entireexposure is finished, the exposure device is in the state shown in FIG.2 and the photosensitive paper 11 is cut by the cutter 12. The exposedphotosensitive paper 11 is guided by the guide roller 14, developed bythe liquid developer 16 and discharged onto the photosensitive paperreceiver 15.

Before the second exposure is started, from the state shown in FIG. 2,the first moving reflection mirror 4 and the illumination light sources7 and 8 move in the direction of arrow D, the second moving reflectionmirror 5 moves in the direction of arrow E, and the third reflectionmirror 6 moves. in the direction of arrow F. In this way, they allreturn to the state shown in FIG. 1.

Here, if the optical path length between the original surface and thelens 9 is kept constant, and when the moving reflection mirrors 4, 5 and6 move in unison with one another, the focal plane can always be kept onthe photosensitive paper. Assuming that each of the moving reflectionmirrors moves from the position shown in solid lines to the positionshown in chain lines and each of the distances of the movements of thesecond and the third moving reflection mirrors 5 and 6 are x, theoptical path length l from the original surface to the lens 9 in thecase of the solid line can be known in FIG. 3 as r,=(&|-2 v2 )2: (n Theoptical path length 1 from the original surface to the lens in the caseof a two-dotted chain line is l (6+ V 2 )x+y (2) Herein y is thedistance of the movement of the first reflection mirror 4. In theequations l and (2 l ,=l, leads to That is, the speed of the firstmoving reflection mirror 4 should be 3.414 times as high as that of thesecond moving reflection mirror 5 and the third moving reflection mirror6.

In the existing reproduction apparatus, there are several kinds, forexample, one in which an original and sensitive paper are both fixed andthey are exposed at the same time just as in an ordinary enlarger,another wherein an original is moved in unison with the movement of aphotosensitive paper which is exposed through a slit, another in which aslit plane is moved in accordance with the movement of a lens, etc.Among them, in the system wherein an original and sensitive paper areboth fixed, the body must become extremely large and it is quitedifficult to illuminate the original uniformly. In the system in whichan original moves together with the photosensitive paper, only a part ofthe original is illuminated through the slit exposure system, and thedevice per se becomes considerably smaller than the system with a fixedoriginal and fixed photosensitive paper and a high quality lens is notrequired. However, since the original itself must be moved, theoperation is difficult and some kinds of originals cannot be used.Furthermore, in a system wherein an original and a photosensitive paperare fixed and a lens and a slit are moved, the size becomes the same asthe first one though it employs a slit exposure system, and thestructure also becomes complicated because the movement of thephotosensitive paper is intermittent.

The invention employs a slit exposure system wherein the internalreflection mirrors move while the original is fixed, and the space whichthe photosensitive paper occupies at the exposure position is so smallthat the device can be made very compact and it is possible to constructa desk-type device. Moreover, it is not necessary to stop thephotosensitive paper so that the invention provides a reproductionapparatus which is simple in structure, easy to handle and high inefficiency. While the present invention has been particularly describedin terms of a specific embodiment thereof, it will be understood thatnumerous deviations therefrom and modifications thereupon may be readilydevised by those skilled in the art without departing from the presentinvention.

What is claimed is:

1. Apparatus for reproducing an image-carrying original onphotosensitive paper, said apparatus comprising a housing for supportingthe original in a first plane, a first reflecting mirror supported insaid housing for movement parallel to said first plane, a secondreflecting mirror facing said first mirror and supported in said housingfor movement along the same axis of movement as said first mirror, athird reflecting mirror supported in said housing for movementperpen;icula r to the axis of movement of the first and secondreflecting mirrors, and illumination means for illuminating saidoriginal, said first, second and third reflecting mirrors being orientedrelative to one another and movable relative to one another atparticular speeds to scan the original and successively reflect an imagethereof from the first to the second to the third mirrors in successionand then onto photosensitive paper which moves in unison with the first,second and third reflecting mirrors whereby to expose the photosensitivepaper.

2. Apparatus as claimed in claim 1 wherein said first reflecting mirrorissupported at an acute angle relative to said first plane. Y

3. Apparatus as claimed in claim 1 including a fixed lens interposedbetween said third reflecting mirror and said photosensitive paper.

4. Apparatus as claimed in claim 1 wherein said illumination means issupported for movement in unison with said first reflecting mirrorparallel to said first plane.

5. Apparatus as claimed in claim 1 including a roller for supportingsaid photosensitive paper in a roll, and guide means for directing aportion of said photosensitive paper from said roller to a position ofexposure in said housing to receive the reflected image.

6. Apparatus as claimed in claim 5 including developing means fordeveloping the image reflected onto said photosensitive paper. I

7. A slit exposure device for a reproduction apparatus which comprises afirst moving reflection mirror making an angle of 45 with respect to afixed original surface, a second moving reflection mirror making anangle of 2230 with the surface, a third moving reflection mirror makingan angle of 6730 with the surface and a fixed lens whose optical axismakes an angle of with respect to the original surface, said firstmoving reflection mirror moving in a direction parallel to the originalsurface at a speed of 2+ times as great as that of the second and thethird reflection mirrors, said second moving reflection mirror moving ina direction at 90 with respect to the original surface in accordancewith the movement of the first moving reflection mirror, said thirdmoving reflection mirror moving in a direction parallel to the originalsurface at the same speed as that of the second moving reflectionmirror, light from the original surface being reflected by the first,the third and the second reflection mirrors in sequence, passing throughsaid fixed lens and being projected through a slit upon a photosensitivepaper which moves in unison with the first, the second and the thirdmoving reflection mirrors.

1. Apparatus for reproducing an image-carrying original onphotosensitive paper, said apparatus comprising a housing for supportingthe original in a first plane, a first reflecting mirror supported insaid housing for movement parallel to said first plane, a secondreflecting mirror facing said first mirror and supported in said housingfor movement along the same axis of movement as said first mirror, athird reflecting mirror supported in said housing for movementperpendicular to the axis of movement of the first and second reflectingmirrors, and illumination means for illuminating said original, saidfirst, second and third reflecting mirrors being oriented relative toone another and movable relative to one another at particular speeds toscan the original and successively reflect an image thereof from thefirst to the second to the third mirrors in succession and then ontophotosensitive paper which moves in unison with the first, second andthird reflecting mirrors whereby to expose the photosensitive paper. 2.Apparatus as claimed in claim 1 wherein said first reflecting mirror issupported at an acute angle relative to said first plane.
 3. Apparatusas claimed in claim 1 including a fixed lens interposed between saidthird reflecting mirror and said photosensitive paper.
 4. Apparatus asclaimed in claim 1 wherein said illumination means is supported formovement in unison with said first reflecting mirror parallel to saidfirst plane.
 5. Apparatus as claimed in claim 1 including a roller forsupporting said photosensitive paper in a roll, and guide means fordirecting a portion of said photosensitive paper from said roller to aposition of exposure in said housing to receive the reflected image. 6.Apparatus as claimed in claim 5 including developing means fordeveloping the image reflected onto said photosensitive paper.
 7. A slitexposure device for a reproduction apparatus which comprises a firstmoving reflection mirror making an angle of 45* with respect to a fixedoriginal surface, a second moving reflection mirror making an angle of22*30'' with the surface, a third moving reflection mirror making anangle of 67*30'' with the surface and a fixed lens whose optical axismakes an angle of 90* with respect to the original surface, said firstmoving reflection mirror moving in a direction parallel to the originalsurface at a speeD of 2+ Square Root 2 times as great as that of thesecond and the third reflection mirrors, said second moving reflectionmirror moving in a direction at 90* with respect to the original surfacein accordance with the movement of the first moving reflection mirror,said third moving reflection mirror moving in a direction parallel tothe original surface at the same speed as that of the second movingreflection mirror, light from the original surface being reflected bythe first, the third and the second reflection mirrors in sequence,passing through said fixed lens and being projected through a slit upona photosensitive paper which moves in unison with the first, the secondand the third moving reflection mirrors.